Chronic Wasting Disease
Author: Katie Ockert
Chronic Wasting Disease
Chronic Wasting Disease (CWD) is a contagious neurological disease that has been found in cervids which include deer, elk and moose. CWD is caused by a misfolded prion; prions are most commonly found in the nervous system and lymphatic (lymph node) system. CWD is a fatal disease with no known cure or treatment, with average time between infection and death being 18-24 months. Chronic Wasting Disease was first confirmed in a free ranging white-tailed deer in 2015; since then a total of 182 deer in Michigan have tested CWD positive/suspect positive as of January 2020. CWD is currently believed to be a cervid specific disease, though current research is ongoing to determine its crossover potential to humans and other animals.
What are the symptoms of CWD?
- Generally, an animal will show no outward signs of CWD until the disease is in its final stages, though it can remain infectious to other deer despite its healthy appearance. If an animal survives to the final stages of CWD the most clear and consistent signs are:
- Extreme weight loss or emaciation
- Lack of coordination
- Drooping head and/or ears
- Excessive drinking and drooling
How is CWD spread through the deer population?
- Prions have been identified in saliva, feces, urine, blood, and semen.
- CWD is thought to be contracted through direct contact with an infected individual or through exposure of prions deposited in the environment by infected deer.
What factors impact the spread of CWD?
- Natural deer movement.
- Baiting, feeding and mineral sites (anything that entices deer to congregate).
- Improper carcass transportation and disposal.
How is CWD detected?
- Conclusive diagnosis can only occur with a laboratory examination of the brain and lymph nodes after death.
- To have your deer tested in Michigan, you may take your deer head to a DNR Check Station, partnering meat processors and taxidermists, or a DNR drop box. To learn more about this process visit the DNR website at Michigan.gov/CWD.
What is being done to address CWD?
- CWD Deer Management Units (see map on the back of this handout) created to surveil deer populations and CWD prevalence.
- Extensive testing of deer statewide, and especially in CWD Core Area and CWD Management Zones.
- Deer carcass movement restrictions.
- Baiting and feeding ban.
- Localized targeted removal
- Encouraging hunters to keep hunting.
Ongoing research to develop more accurate CWD tests, more effective harvest regulations, and predictive models to direct more effective and efficient surveillance protocols.